CN112566743A

CN112566743A - Method for confirming gripping accuracy of chuck, method for replacing chuck jaws, and apparatus for confirming gripping accuracy of chuck

Info

Publication number: CN112566743A
Application number: CN201980053313.4A
Authority: CN
Inventors: 永翁博
Original assignee: Howa Machinery Ltd
Current assignee: Howa Machinery Ltd
Priority date: 2018-08-10
Filing date: 2019-08-09
Publication date: 2021-03-26
Anticipated expiration: 2039-08-09
Also published as: US11794301B2; WO2020032237A1; US20210308817A1; KR20210024136A; KR102507946B1; EP3834971A4; JP7020557B2; TW202019590A; TWI719582B; EP3834971A1; JPWO2020032237A1

Abstract

The method for confirming the gripping accuracy of the chuck comprises the following steps: a grasping step of grasping the object to be measured by the claw, a moving step, and a measuring step. In the moving step, the moving body driving unit is driven to move the moving body provided with the measuring instrument capable of measuring the vibration of the object to be measured to a position where the measuring instrument can measure the vibration of the object to be measured. In the measuring step, the vibration of the object to be measured is measured by the measuring instrument while the chuck is rotated by driving the rotation driving section.

Description

Method for confirming gripping accuracy of chuck, method for replacing chuck jaws, and apparatus for confirming gripping accuracy of chuck

Technical Field

The present invention relates to a chuck grip accuracy confirming method, a chuck jaw replacing method, and a chuck grip accuracy confirming device.

Background

Conventionally, when the size of a workpiece to be machined changes or when wear occurs due to long-term use, a claw of a chuck body attached to a chuck is replaced. Further, the gripping accuracy of the chuck is confirmed when the claws are replaced. When replacing a claw with the automatic claw replacement device as disclosed in patent document 1, the operator grasps the master batch with the chuck and reads the measurement value of the measuring device while rotating the chuck to measure the vibration of the master batch and check the grasping accuracy of the chuck when replacing the claw. In addition, the operator may confirm the gripping accuracy of the chuck by measuring the vibration of the workpiece machined using the replaced claws.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 3185816

Disclosure of Invention

Technical problem to be solved by the invention

However, when the vibration of the master batch or the workpiece is measured by an operator, there is a problem in reliability such as a reading error of the measurement value or a measurement variation.

In view of the above problems, an object of the present invention is to provide a chuck gripping accuracy confirming method, a chuck jaw exchanging method, and a chuck gripping accuracy confirming device that can improve reliability.

Technical scheme for solving technical problem

The invention relates to a method for confirming the gripping precision of a chuck,

in the method for confirming gripping accuracy of a chuck, gripping a measurement object to a jaw of the chuck to confirm the gripping accuracy, the method includes:

a grasping step of grasping the measurement object by the claw;

a moving step of moving a moving body, which is provided with a measuring instrument capable of measuring vibration of the object to be measured, to a position where the measuring instrument can measure the vibration of the object to be measured by driving a moving body driving unit; and

and a measuring step of measuring the vibration of the object to be measured by the measuring instrument while rotating the chuck by driving a rotation driving unit.

In the above-described gripping accuracy confirmation method of the chuck,

the movable body driving unit may include an elevation driving unit that elevates the movable body, an axial movement driving unit that moves the movable body in the axial direction of the chuck, and a lateral movement driving unit that moves the movable body in the lateral direction when viewed in the axial direction.

In the above-described gripping accuracy confirmation method of the chuck,

the measuring step may include a first measuring step of measuring vibration of the cylindrical outer peripheral surface of the object to be measured, and a second measuring step of measuring vibration of the distal end surface of the object to be measured.

In the above-described gripping accuracy confirmation method of the chuck,

the measuring device may include a first measuring device capable of measuring vertical displacement and a second measuring device capable of measuring horizontal displacement.

In the method for confirming the gripping accuracy of the chuck, the chuck may be,

in the moving step, the moving body is moved to a position where the first measuring device can measure the vibration of the object to be measured by driving the moving body driving unit,

in the first measuring step, the vibration of the cylindrical outer peripheral surface of the object to be measured is measured by the first measuring device,

after the first measuring step, the movable body is moved to a position where the second measuring instrument can measure the vibration of the object to be measured by driving the movable body driving unit,

in the second measuring step, the vibration of the distal end surface of the object to be measured is measured by the second measuring device.

In the above-described gripping accuracy confirmation method of the chuck,

in the grasping step, the object to be measured may be carried to the chuck by the moving body.

Further, the present invention provides a method of replacing a jaw of a chuck, including: a replacement step of replacing the chuck jaws; and

a gripping accuracy confirmation step of confirming the gripping accuracy of the chuck after the replacement step by using the gripping accuracy confirmation method of the chuck.

Further, the present invention is a chuck grip accuracy confirming device,

the gripping accuracy confirmation apparatus for gripping a measurement object to the jaws of the chuck and confirming the gripping accuracy includes:

a rotation driving unit that rotates the chuck;

a movable body provided movably with respect to the chuck;

a movable body driving unit that moves the movable body relative to the measurement target object;

a measuring device that is provided on the movable body and measures vibration of the object to be measured; and

a control part for controlling the operation of the display device,

the control unit controls the rotation driving unit, the movable body driving unit, and the measuring device such that the movable body is moved to a position where the measuring device can measure the vibration of the object to be measured, and then the vibration of the object to be measured is measured by the measuring device while rotating the chuck.

In the gripping accuracy confirmation apparatus for a chuck as described above,

In the gripping accuracy confirmation apparatus for a chuck, it is preferable that,

the control unit controls the movable body driving unit and the measuring device such that the movable body moves to a position where the first measuring device can measure the vibration of the cylindrical outer peripheral surface of the object to be measured and the vibration of the cylindrical outer peripheral surface of the object to be measured is measured by the first measuring device, and the movable body moves to a position where the second measuring device can measure the vibration of the distal end surface of the object to be measured and the vibration of the distal end surface of the object to be measured is measured by the second measuring device.

In the gripping accuracy confirmation apparatus for a chuck as described above,

the movable body may be configured to convey the object to be measured to the chuck.

Effects of the invention

According to the present invention, reliability can be improved.

Drawings

Fig. 1 is a view of the gripping accuracy confirmation apparatus for a chuck and the chuck of the present embodiment as viewed in the axial direction, and is a view showing a state in which vibration of the cylindrical outer peripheral surface of the master batch gripped by the chuck is measured.

Fig. 2 is a view in the Z direction of fig. 1.

Fig. 3 is a diagram showing a state in which the loader of fig. 2 handles the master batch.

Fig. 4 is a schematic view illustrating the automatic claw exchanging apparatus of fig. 2.

Fig. 5 is a view showing a state where vibration of a front end surface of the master batch gripped by the chuck is measured in the gripping accuracy confirmation apparatus of the chuck of fig. 2.

Fig. 6 is a view showing a state where the operation of the claws is measured in the gripping accuracy confirmation apparatus for a chuck of fig. 2.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, an example in which the chuck is a chuck of a machine tool such as an NC lathe will be described. In the drawings attached to the present specification, the scale, the vertical and horizontal size ratios, and the like are appropriately changed from the actual ones and exaggerated for the convenience of illustration and understanding.

First, a chuck of a machine tool will be schematically described.

As shown in fig. 1 and 2, the chuck 1 includes a chuck main body 3 and claws 4, the chuck main body 3 is fixed to a spindle 10 of a machine tool, and the claws 4 grip (grasp) a workpiece W or a master batch MP to be processed. The chuck 1 of the present embodiment includes three claws 4. As shown in fig. 3, the processed workpiece W and the master batch MP are conveyed to the chuck 1 by a loader 2 exemplified as a conveying device.

The workpiece W to be machined held by the chuck 1 is machined by a tool rest (not shown) including a plurality of tools. As shown in fig. 2, the chuck 1 is rotatable by a rotation driving unit 11 via a spindle 10, and when machining is performed, the rotation driving unit 11 is driven, and the chuck 1 rotates together with the spindle 10, whereby the workpiece W is machined while rotating. Depending on the processing content, the workpiece W may be processed in a stopped state without being rotated. The tool post is movable in the axial direction X of the chuck 1, and is also movable in the lateral direction Y (or horizontal direction) and up-and-down direction as viewed from the axial direction X.

As shown in fig. 4, an automatic claw changer 12 as described in, for example, japanese patent No. 3185816 is provided above the chuck 1. The claw 4 attached to the chuck body 3 can be automatically replaced by the automatic claw replacement device 12. For example, when the size of the workpiece W to be machined changes or when wear occurs due to long-term use, the claw 4 is replaced. The claw 4 is formed to correspond to the size of the workpiece W to be processed (more specifically, the outer diameter of the base end portion of the workpiece W), and can grip the workpiece W. Therefore, the plurality of types of claws 4 are stored in a magazine (not shown) of the automatic claw changer 12.

As shown in fig. 4, the automatic claw changer 12 includes a finger 13 capable of being lifted and lowered and a claw lift driving unit 14 for lifting and lowering the finger 13. The finger part 13 includes a key piece 13a engageable with a hooking groove 15a of a mounting block 15 provided on the upper portion of the claw 4. The tab 13a of the finger portion 13 engages with the hooking groove 15a of the mounting block 15, and the claw 4 is moved up and down by driving the claw lift driving portion 14. In addition, the fingers 13 are also movable in the axial direction X of the chuck 1.

As shown in fig. 2 and 4, the claw 4 includes a bottom jaw 16 and a top jaw 17, the bottom jaw 16 is fitted into the mounting groove 3a provided in the chuck body 3, and the top jaw 17 is attached to the bottom jaw 16 and projects from an end surface (end surface on the right side in fig. 2) of the chuck body 3. The mounting groove 3a extends in the radial direction and opens on the outer peripheral surface of the chuck body 3. As shown in fig. 1 and 4, the mounting groove 3a is also open at the end surface of the chuck body 3. The bottom jaw 16 to which the top jaw 17 is attached is inserted into the mounting groove 3a from the radially outer side (from above) and moved radially inward, whereby the claw 4 can be attached to the chuck 1. At this time, the claw 4 moves radially inward to a position where the driving of the claw raising/lowering driving unit 14 is stopped. When the claw 4 is removed, the claw 4 is moved outward in the radial direction and is pulled out from the mounting groove 3 a.

Three main jaws 18 are provided inside the chuck body 3 corresponding to the three jaws 4. The three main jaws 18 are movable in synchronization in the radial direction by a pawl driving section, not shown. As shown in fig. 4, a claw engaging and disengaging device 19 is provided in the main jaw 18, and the bottom jaw 16 can be engaged with and disengaged from the main jaw 18. That is, the claw release device 19 includes an engaging member 20, and rack teeth 20a are provided on a distal end surface (a surface on the bottom jaw 16 side) of the engaging member 20. The rack teeth 20a can mesh with rack teeth 16a provided on the rear end surface (surface on the main jaw 18 side) of the bottom jaw 16. The engaging member 20 is movable in the axial direction X, and when the engaging member 20 advances toward the bottom jaw 16, the rack teeth 20a of the engaging member 20 engage with the rack teeth 16a of the bottom jaw 16. Thereby, the bottom jaw 16, the top jaw 17, and the main jaw 18 can be integrally moved in the radial direction. On the other hand, when the engaging member 20 is retracted from the bottom jaw 16, the engagement between the rack teeth 20a of the engaging member 20 and the rack teeth 16a of the bottom jaw 16 is released. Thereby, the bottom jaw 16 and the top jaw 17 can be moved in the radial direction separately from the main jaw 18, and the claw 4 can be replaced.

In order to clamp the master batch MP, each top jaw 17 moves radially inward together with the bottom jaw 16 and the main jaw 18, and as shown in fig. 1 and 2, an inner peripheral abutment surface 17a provided at an inner end portion of each top jaw 17 abuts against a base end outer peripheral abutment surface MPc (described later) of the master batch MP (the chuck 1 is closed). The inner peripheral contact surface 17a of each of the top jaws 17 is pressed against the base end outer peripheral contact surface MPc of the master batch MP, whereby the master batch MP is gripped by the claw 4.

On the other hand, when the master batch MP is removed, the top jaws 17 move radially outward together with the bottom jaw 16 and the main jaw 18, and the inner peripheral contact surfaces 17a of the top jaws 17 are separated from the master batch MP (the chuck 1 is opened). Thereby, the master batch MP is detached from the claw 4.

When such a claw 4 is replaced, the gripping accuracy of the replaced claw 4 with respect to the chuck 1 is checked in order to maintain the machining accuracy of the workpiece W. That is, as described above, when the bottom jaw 16 of the claw 4 is engaged with the main jaw 18 by the claw engaging and disengaging device 19, the bottom jaw can move in the radial direction integrally with the main jaw 18 and can move in synchronization with the bottom jaw 16 of the other claw 4. However, when the claws 4 are attached to the chuck main body 3 in a state where the bottom jaws 16 are different in position in the radial direction in each claw 4, it is difficult for each top jaw 17 to uniformly abut against the base end outer periphery abutment surface MPc of the master batch MP, and the grip of the chuck 1 is deviated. When the workpiece W is held and rotated by the chuck 1 in this state, vibration of the workpiece W increases, and the machining accuracy of the workpiece W decreases. The gripping accuracy confirming device (hereinafter, simply referred to as the gripping accuracy confirming device 21) of the chuck 1 according to the present embodiment is a device for solving such a problem, and is a device for grasping the object to be measured (hereinafter, referred to as the master batch MP as an example) by the claws 4 of the chuck 1 as described above and confirming the gripping accuracy.

As shown in fig. 1 and 2, the gripping accuracy confirmation apparatus 21 of the present embodiment includes a rotation drive unit 11, a hand 22 (moving body), a loader drive unit 23 (moving body drive unit), a measuring instrument 6, and a control unit 24, wherein the rotation drive unit 11 rotates the chuck 1, and the hand 22 is provided movably with respect to the chuck 1.

As shown in fig. 2 and 3, the master batch MP has a cylindrical outer peripheral surface MPa, a leading end surface MPb, a base end outer peripheral abutment surface MPc, and a base end surface MPd. In a state where the master batch MP is gripped in the chuck 1, the cylindrical outer peripheral surface MPa extends in the axial direction X, and the leading end surface MPb and the base end surface MPd are perpendicular to the axial direction X. The leading end surface MPb is located on the side opposite to the chuck 1 side, and the base end surface MPd is located on the chuck 1 side. The base end outer peripheral abutment surface MPc is a portion located on the base end surface MPd side and gripped by the claw 4. A plurality of types of master batches MP are stored in a storage (not shown) corresponding to the work W. That is, a plurality of types of master batches MP having different outer diameters of the base end outer peripheral contact surfaces MPc are stored in the magazine.

As shown in fig. 1 and 2, the loader 2 has a hand 22 (moving body), and the hand 22 is provided movably with respect to the master batch MP and the chuck 1. As described above, the loader 2 is a device for transferring the master batch MP to the cartridge 1, and the hand 22 can transfer the master batch MP to the cartridge 1. More specifically, as shown in fig. 3, a pair of claws 25 for holding the master batch MP are attached to the hand 22 of the loader 2, and the master batch MP is held between the pair of claws 25. The gripper 25 is attached to one side surface of the rectangular parallelepiped hand 22. The loader 2 carries the master batch MP to a position where it can be held by the claws 4 of the cartridge 1, and carries it from the cartridge 1 to the magazine. The loader 2 can also convey the workpiece W in the same manner as the master batch MP.

The hand 22 of the loader 2 is moved relative to the chuck 1 by a loader drive unit 23 (moving body drive unit). The loader drive unit 23 includes a loader lift drive unit 26, an axial movement drive unit 27, and a lateral movement drive unit 28, the loader lift drive unit 26 lifting and lowering the hand 22, the axial movement drive unit 27 moving the hand 22 in the axial direction X of the chuck 1, and the lateral movement drive unit 28 moving the hand 22 in the lateral direction Y when viewed in the axial direction X. More specifically, a cross rail 29 extending in the lateral direction Y (or horizontal direction) as viewed in the axial direction X is mounted to the main body of the machine tool, and the first traveling table 30 is capable of traveling along this cross rail 29. The first traveling base 30 may have a lateral movement driving unit 28 built therein. Further, the axial guide rail 31 extending in the axial direction X is movable in the axial direction X relative to the first traveling carriage 30. A second traveling base 32 is attached to the axial guide rail 31, and the second traveling base 32 can travel in the axial direction X together with the axial guide rail 31. The axial movement driving unit 27 may be internally provided in the first traveling base 30. The vertically extending lift rod 33 is movable up and down with respect to the second traveling base 32. The hand 22 is attached to the lower end of the lifter 33. The second traveling base 32 may have the loader lift drive unit 26 built therein. In this way, the hand 22 of the loader 2 is movable in the axial direction X, the lateral direction Y, and the up-down direction with respect to the chuck 1. The second traveling base 32 may include a loader rotation driving unit 34 for rotating the lift lever 33. The loader rotation driving unit 34 may rotate the lift lever 33 and the hand 22 around a central axis extending in the vertical direction of the lift lever 33.

As shown in fig. 1 and 2, a measuring device 6 for measuring vibration of the master batch MP is attached to the hand 22 of the loader 2. The measuring device 6 includes a first sensor 6a (first measuring device) and a second sensor 6b (second measuring device), and the first sensor 6a can measure vertical displacement and the second sensor 6b can measure horizontal displacement. The first sensor 6a and the second sensor 6b are attached to the hand 22 via the attachment member 5. The attachment member 5 is attached to the side surface opposite to the above-described gripper 25 among the four side surfaces of the rectangular parallelepiped hand portion 22. The first sensor 6a is mounted on the lower surface of the rectangular parallelepiped-shaped mounting member 5 so as to be able to contact or approach the master batch MP from above, thereby measuring the vibration of the master batch MP. The second sensor 6b is mounted on a side surface (a side surface opposite to the gripper 25) of the mounting member 5, and can contact or approach the master batch MP in the horizontal direction, thereby measuring the vibration of the master batch MP. Examples of the first sensor 6a and the second sensor 6b include a displacement sensor, a contact probe, and the like, but are not limited thereto as long as the vibration of the master batch MP can be measured. In addition, the first sensor 6a and the second sensor 6b may be contact sensors that contact the master batch MP to measure the vibration, or may be non-contact sensors that are separate from the master batch MP to measure the vibration. Here, the vibration refers to displacement of a measurement target surface (cylindrical outer peripheral surface MPa or leading end surface MPb) of the master batch MP during rotation of the master batch MP.

The control unit 24 controls the rotation driving unit 11, the loader driving unit 23, the measuring device 6, and the like. More specifically, the control section 24 controls the rotation drive section 11, the loader drive section 23, and the measuring instrument 6 to first move the hand 22 to a position where the measuring instrument 6 can measure the vibration of the master batch MP, then rotate the chuck 1, and then cause the measuring instrument 6 to measure the vibration of the master batch MP. When measuring the vibration of the master batch MP, the control unit 24 may perform a first measurement step (see fig. 2) of measuring the vibration of the cylindrical outer peripheral surface MPa of the master batch MP by the first sensor 6a and a second measurement step (see fig. 5) of measuring the vibration of the leading end surface MPb of the master batch MP by the second sensor 6 b.

For example, the controller 24 may control the loader drive unit 23 and the measuring device 6 so that the hand 22 moves to a position where the first sensor 6a can measure the vibration of the cylindrical outer peripheral surface MPa of the master batch MP to perform the first measurement step and so that the hand 22 moves to a position where the second sensor 6b can measure the vibration of the leading end surface MPb of the master batch MP to perform the second measurement step. In the first measurement step, the vibration of the cylindrical outer peripheral surface MPa of the master batch MP may be measured at the first measurement position and the second measurement position. The first measurement position thereof is a position at which the vibration of the cylindrical outer peripheral surface Mpa at the portion on the chuck main body 3 side (the portion on the base end side of the master batch MP) in the cylindrical outer peripheral surface Mpa of the master batch MP can be measured. The second measurement position is a position at which the vibration of the cylindrical outer peripheral surface MPa at a portion (a portion on the leading end side of the master batch MP) on the opposite side of the chuck main body 3 in the cylindrical outer peripheral surface MPa of the master batch MP can be measured. In fig. 2, the first measurement position is indicated by a two-dot chain line, and the second measurement position is indicated by a solid line. In the second measurement process, as shown in fig. 5, the vibration of the master batch MP may also be measured at the third measurement position. The third measurement position is a position at which the vibration of the leading end surface MPb (end surface on the side opposite to the chuck main body 3) of the master batch MP can be measured. The third measurement position is preferably set to a position at which the vibration of the leading end surface MPb at the outer peripheral edge side of the master batch MP in the leading end surface MPb can be measured.

Further, the control portion 24 records the measurement values of the vibration of the master batch MP measured by the first sensor 6a and the second sensor 6 b. The measured values can also be recorded in association with the rotational phase of the chuck 1. The measurement by the

sensors

6a and 6b may be performed at a predetermined phase interval, for example.

Further, the control section 24 determines whether the vibration of the master batch MP is normal or abnormal based on the measurement value of the vibration of the master batch MP measured by the measuring instrument 6. For example, the determination of whether the vibration is normal or abnormal may be made by determining whether the amplitude of the vibration is larger than a predetermined reference value. The reference value may be set for each of the three measurement positions, and it may be determined at each measurement position whether the measurement position is normal or abnormal. In addition, when there is an abnormality in the measurement value obtained at any one of the measurement positions of the vibration of the master batch MP at the three measurement positions, the determination of whether it is normal or abnormal may be determined as abnormal.

If it is determined to be abnormal, the control unit 24 may notify an alarm. For example, an abnormality message may be displayed on the display of the machine tool. Alternatively, the abnormality may be notified by lighting or blinking of a lamp, or may be notified by an alarm sound such as a buzzer. The abnormality may be notified during the measurement of the vibration of the master batch MP or after the measurement is completed.

Next, a method of confirming the gripping accuracy of the chuck 1 according to the present embodiment will be described. Here, an example of a method for confirming the gripping accuracy of the chuck 1 when the method for replacing the claw 4 of the chuck 1 is performed will be described.

First, the claw 4 is replaced as a claw replacement step. More specifically, first, by rotating the chuck 1, the claw 4 to be replaced among the three claws 4 attached to the chuck 1 is positioned at a position where it can be pulled out upward from the attachment groove 3 a. Next, the finger part 13 of the automatic claw changer 12 is lowered, advanced in the axial direction X of the chuck 1 toward the hooking groove 15a of the mounting block 15 of the claw 4, and the key piece 13a of the finger part 13 is locked to the hooking groove 15a of the mounting block 15. Subsequently, the engagement member 20 of the claw release device 19 is retracted to release the engagement with the main jaw 18. Thereafter, the finger parts 13 are raised to pull the claws 4 out of the mounting grooves 3a of the chuck body 3. Subsequently, the extracted claw 4 is conveyed to a magazine (not shown) and stored, and the other claws 4 are engaged with the finger parts 13. Subsequently, the finger parts 13 are conveyed and lowered above the mounting groove 3a, and inserted into the mounting groove 3a of the chuck body 3. Subsequently, the engagement member 20 of the claw release device 19 is advanced, and the bottom jaw 16 of the claw 4 inserted into the mounting groove 3a is engaged with the main jaw 18. Next, the key pieces 13a of the finger parts 13 are moved in the axial direction X of the chuck 1 and retreated from the hooking grooves 15a of the mounting block 15. Then, the finger parts 13 are raised and retracted. By performing such an operation on the other claws 4, the three claws 4 attached to the chuck 1 can be replaced.

After the claw replacement step, the gripping accuracy of the chuck 1 is checked as a gripping accuracy checking step.

First, as the grasping step, the master batch MP is held by the claw 4. More specifically, first, the hand 22 of the loader 2 clamps the desired master batch MP stored in a magazine (not shown) to the gripper 25. Subsequently, the master batch MP is conveyed to a position where it can be held by the claws 4 of the chuck 1. At this time, the top jaw 17 of each claw 4 is located radially outward of the position where the master batch MP is gripped. When the master batch MP is conveyed, the base end surface MPd of the master batch MP is positioned on the chuck 1 side, and therefore the hand 25 is oriented toward the chuck 1 side with respect to the mounting member 5. When the master batch MP reaches the position where it can be gripped by the claws 4 of the chuck 1, the base end surface MPd of the master batch MP abuts against the abutting end surface 17b which is provided inside the inner peripheral abutting surface 17a of the top jaw 17 and is perpendicular to the axial direction X. Subsequently, the main jaws 18 are synchronously moved radially inward, and the top jaws 17 are synchronously moved radially inward in accordance with the movement. Thereby, the inner peripheral abutment surface 17a of the top jaw 17 abuts against the base end outer peripheral abutment surface MPc of the master batch MP, and the master batch MP is clamped by the claws 4. Thereafter, the hand 22 releases the grip of the master batch MP. Thus, the master batch MP is held by the three claws 4.

After the grasping step, as a moving step, the hand 22 is moved to a position where the measuring device 6 can measure the vibration of the master batch MP. More specifically, the first sensor 6a or the second sensor 6b of the measuring instrument 6 is moved to a desired position by driving the loader elevation drive section 26, the axial movement drive section 27, and the lateral movement drive section 28 of the loader drive section 23. Further, the posture of the hand 22 may be changed by driving the loader rotation driving unit 34. Here, as shown in fig. 1, the orientation of the hand 22 is changed such that the mounting member 5 is located on the left side and the finger 25 is located on the right side when viewed from the front end toward the base end of the master batch MP in the axial direction X. Further, the hand 22 may be moved to a position where the first sensor 6a can measure the vibration of the master batch MP. Here, the hand 22 is moved to a first measurement position (position indicated by a two-dot chain line in fig. 2) at which the first sensor 6a can measure the vibration of the master batch MP in the portion of the cylindrical outer peripheral surface MPa of the master batch MP on the base end side of the master batch MP.

After the moving process, as a measuring process, the vibration of the master batch MP is measured by the first sensor 6a of the measuring instrument 6. The measurement step may include a first measurement step of measuring the vibration of the cylindrical outer peripheral surface MPa of the master batch MP by the first sensor 6a and a second measurement step of measuring the vibration of the leading end surface MPb of the master batch MP by the second sensor 6 b.

For example, a first measurement process is first performed. At this time, the vibration of the cylindrical outer peripheral surface MPa of the master batch MP is measured at the base end side of the master batch MP by the first sensor 6a positioned at the first measurement position. During this time, the rotation driving section 11 is driven, and the master batch MP is rotated together with the spindle 10 and the chuck 1. For example, the measurement of the vibration of the cylinder outer peripheral surface MPa may be performed while the chuck 1 is rotated until one claw 4 of the three claws 4 passes through the other claw 4 to reach the remaining claws 4. The rotation angle of the chuck 1 at this time is 240 ° (180 ° in the case where two claws 4 are provided) in the case where three claws 4 are provided as in the present embodiment. Alternatively, the vibration of the cylindrical outer peripheral surface MPa may be measured while the chuck 1 is rotated once (rotated 360 °), and the rotation angle at the time of measurement may be arbitrary as long as the vibration of the master batch MP can be measured efficiently. The obtained measurement value is recorded in the control unit 24 in association with the rotation phase of the chuck 1.

Next, the hand 22 is moved to a second measurement position (position indicated by a solid line in fig. 2) at which the first sensor 6a can measure the vibration of the master batch MP at a portion of the cylindrical outer peripheral surface MPa of the master batch MP on the leading end side thereof. Then, the vibration of the cylindrical outer peripheral surface MPa of the master batch MP in the portion on the leading end side of the master batch MP is measured by the first sensor 6a positioned at the second measurement position. During this time, the rotation driving unit 11 is driven to rotate the master batch MP together with the spindle 10 and the chuck 1, as in the measurement at the first measurement position. The obtained measurement value is recorded in the control unit 24 in association with the rotation phase of the chuck 1.

Next, the hand 22 is moved to a position where the second sensor 6b can measure the vibration of the master batch MP. Here, the hand 22 is moved to a third measurement position (position shown in fig. 5) at which the second sensor 6b can measure the vibration of the master batch MP at the front end surface MPb of the master batch MP. Then, a second measurement process is performed. At this time, the vibration of the leading end surface MPb of the master batch MP is measured by the second sensor 6b positioned at the third measurement position. During this time, the rotation driving unit 11 is driven to rotate the master batch MP together with the spindle 10 and the chuck 1, as in the measurement at the first measurement position. The obtained measurement value is recorded in the control unit 24 in association with the rotation phase of the chuck 1.

In this way, after the measuring device 6 is moved to the measurement position of the master batch MP held by the chuck 1, the chuck 1 is automatically rotated, and the vibration of the master batch MP can be automatically measured. After the end of the measurement, the hand 22 may also be set back to a position separated from the master batch MP.

After the measuring process, as a judging process, whether the vibration of the master batch MP is normal or abnormal is judged based on the measured value of the vibration of the master batch MP. If it is determined to be abnormal, an abnormality is notified. In this case, the operator may correct (e.g., remount) the mounting of the claw 4 to the chuck body 3 in which the mounting abnormality has occurred, and confirm the gripping accuracy again.

In a case where it is judged that the vibration of the master batch MP is normal, the master batch MP is detached from the claw 4. In this case, first, the hand 22 of the loader 2 holds the master batch MP. Subsequently, the main jaws 18 are synchronously moved radially outward, and the top jaws 17 are synchronously moved radially outward in accordance with the movement. Thereby, the inner peripheral contact surface 17a of the top jaw 17 is separated from the base end outer peripheral contact surface MPc of the master batch MP, and the grip of the master batch MP by the claw 4 is released. Then, the master batch MP was transported to a warehouse and stored.

Next, the hand 22 clamps a desired workpiece W stored in the magazine and conveys the workpiece W to a position where the workpiece W can be clamped by the claws 4 of the chuck 1. At this time, the top jaw 17 of each claw 4 is positioned radially outward of the position where the workpiece W is gripped. When the workpiece W reaches a position where it can be gripped by the jaws 4 of the chuck 1, the base end surface of the workpiece W abuts against the abutment end surface 17b of the top jaw 17. Subsequently, the main jaws 18 are synchronously moved radially inward, and the top jaws 17 are synchronously moved radially inward in accordance with the movement. Thereby, the inner peripheral contact surface 17a of the top jaw 17 contacts the workpiece W, and the workpiece W is clamped by the claw 4. Thereafter, the hand 22 releases the clamping of the workpiece W. Thus, the workpiece W is clamped by the three claws 4.

Thereafter, the workpiece W held by the claw 4 is machined by a tool of a tool rest, not shown. As described above, after the claw 4 is replaced and before the workpiece W is processed, the gripping accuracy of the claw 4 is confirmed, and it is determined that the vibration of the master batch MP is normal. Therefore, the workpiece W can be gripped by the claw 4 determined to be normal with the gripping accuracy confirmed, and the machining accuracy of the workpiece W can be ensured.

Thus, the operator does not need to measure the vibration, and the problems of reading error of the measured value, measurement deviation and the like of the operator can be avoided. Further, by correlating the measured value of the vibration measured by the measuring device 6 with the rotational phase of the chuck 1, it is possible to easily recognize the rotational phase in which the measured value of the vibration is abnormal. That is, in the case where the master batch MP is long, since the chuck 1 is separated from the measurement position of the vibration, it is difficult to simultaneously observe the measurement value of the vibration and the rotational phase of the chuck 1. However, according to the present embodiment, even if the master batch MP is long, the rotational phase of the chuck 1 in which the measured value of the vibration is abnormal can be easily recognized. Therefore, the claw 4 having the mounting abnormality can be easily determined, and the mounting correction work of the claw 4 can be efficiently performed. Further, since the gripping accuracy of the chuck 1 can be confirmed before the workpiece W is machined after the claw 4 attached to the chuck body 3 is replaced, when the workpiece W with poor machining is found, it can be easily determined that the poor machining occurs due to a cause other than the replaced claw 4 (such as a tool or a mechanical failure).

The gripping accuracy confirmation device 21 of the chuck 1 according to the present embodiment can also be used to confirm the operation state of the claws 4. That is, the mechanism for moving the three claws 4 in the radial direction is constituted by the main jaw 18 and the like as described above, but the grasping accuracy confirmation device 21 of the present embodiment can be used to confirm whether the mechanism is normal or abnormal. In this case, as shown in fig. 6, when the chuck 1 is opened by moving the claws 4 radially outward, the positions of the outer peripheral surfaces of the claws 4 may be measured by the first sensor 6a or the second sensor 6b of the measuring instrument 6. When the positions of the outer peripheral surfaces of the claws 4 are different, it can be determined that an abnormality has occurred in the mechanism. Further, it is also possible to determine whether the mechanism is normal or abnormal by collecting and analyzing the measured value of the position of the outer peripheral surface of one of the claws 4 as data. When it is determined that an abnormality has occurred, the operator can correct the mechanism. Therefore, preventive maintenance of the chuck 1 can be facilitated.

As described above, according to the present embodiment, by driving the loader drive section 23, the hand 22 of the loader 2 on which the measuring device 6 is mounted is moved to a position where the measuring device 6 can measure the vibration of the master batch MP, and the measuring device 6 measures the vibration of the master batch MP at the position. Thereby, the vibration of the master batch MP can be automatically measured, and an operator can be not required to perform the operation. Therefore, the reliability of confirmation of the gripping accuracy of the chuck 1 after the replacement of the claws 4 can be improved.

Further, according to the present embodiment, the loader drive section 23 includes a loader lift drive section 26, an axial direction movement drive section 27, and a lateral direction movement drive section 28, the loader lift drive section 26 moves the hand 22 up and down, the axial direction movement drive section 27 moves the hand 22 in the axial direction X of the chuck 1, and the lateral direction movement drive section 28 moves the hand 22 in the lateral direction Y when viewed in the axial direction X. This makes it possible to easily move the hand 22 to which the measuring device 6 is attached to a position where the measuring device 6 can measure the vibration of the master batch MP. Therefore, the measurement accuracy of the measurement value of the vibration of the measuring instrument 6 can be ensured, and the reliability of confirmation of the gripping accuracy of the chuck 1 can be improved.

Further, according to the present embodiment, as the first measurement step, the vibration of the cylindrical outer peripheral surface MPa of the master batch MP is measured, and as the second measurement step, the vibration of the leading end surface MPb of the master batch MP is measured. Thereby, the vibration of the master batch MP can be measured at different positions. Therefore, the reliability of confirmation of the gripping accuracy of the chuck 1 can be improved.

Further, according to the present embodiment, the measuring device 6 includes the first sensor 6a and the second sensor 6b, and the first sensor 6a can measure the vertical displacement and the second sensor 6b can measure the horizontal displacement. Thus, the first sensor 6a can measure the vibration of the cylindrical outer peripheral surface MPa of the master batch MP, and the second sensor 6b can measure the vibration of the leading end surface MPb of the master batch MP. Therefore, the amount of movement of the hand 22 can be reduced when the measurement is shifted from the first measurement step to the second measurement step. Therefore, the measurement time of the vibration of the master batch MP can be shortened.

According to the present embodiment, the loader drive unit 23 is driven to move the hand 22 to a position where the first sensor 6a can measure the vibration of the master batch MP, and the first measurement step is performed. Then, the loader drive unit 23 is driven to move the hand 22 to a position where the second sensor 6b can measure the vibration of the leading end surface MPb of the master batch MP, and the second measurement step is performed. Therefore, the vibration of the master batch MP can be automatically measured at different positions, and an operator can be not required to perform the operation. Therefore, the reliability of confirmation of the gripping accuracy of the chuck 1 after the replacement of the claws 4 can be improved.

In addition, according to the present embodiment, the master batch MP is held by the hand 22 and conveyed to the chuck 1. This enables the master batch MP to be automatically gripped by the claws 4. Therefore, the gripping accuracy of the chuck 1 after replacing the claws 4 can be easily confirmed, and the operator can be not required to perform the operation.

In the above embodiment, an example in which the vibration of the master batch MP held by the claws 4 is measured to confirm the gripping accuracy of the chuck 1 as an example of the object to be measured is described. However, the present invention is not limited to this, and the gripping accuracy of the chuck 1 may be confirmed by measuring the vibration of the workpiece W held by the claws 4. In this case, the gripping accuracy of the chuck 1 may be confirmed before the workpiece W is machined, or the gripping accuracy of the chuck 1 may be confirmed after the workpiece W is machined.

In addition, in the above-described embodiment, the following example is explained: the measuring device 6 for measuring the vibration of the master batch MP has a first sensor 6a capable of measuring the displacement in the vertical direction and a second sensor 6b capable of measuring the displacement in the horizontal direction. However, the configuration of the measuring instrument 6 is not limited thereto. The number of the sensors may be one or more than three. For example, the second sensor 6b may be positioned at a position corresponding to the first measurement position and/or a position corresponding to the second measurement position on the side of the master batch MP to measure the vibration of the cylindrical outer peripheral surface MPa of the master batch MP.

In the above-described embodiment, the following example is explained: the vibration of the cylindrical outer peripheral surface MPa of the master batch MP is measured at the first measurement position (the portion on the base end side of the master batch MP) and the second measurement position (the portion on the leading end side of the master batch MP), respectively, and the vibration of the leading end surface MPb of the master batch MP is measured at the third measurement position. However, the present invention is not limited to this, and as long as the reliability of the confirmation of the gripping accuracy of the chuck 1 can be ensured, the gripping accuracy of the chuck 1 may be determined by measuring the vibration of the master batch MP at any one of the three measurement positions.

In the above-described present embodiment, an example in which the gripping accuracy of the chuck 1 is checked when the method of replacing the claws 4 of the chuck 1 is performed is described. However, the present invention is not limited to this, and even when the claw 4 is not replaced, the gripping accuracy of the chuck 1 can be confirmed when it is assumed that the claw 4 is worn due to long-term use.

In the above-described embodiment, the following example is explained: a measuring instrument 6 is provided on a hand 22 of the loader 2 that conveys the processed workpiece W and the master batch MP via a mounting member 5. However, it is not limited thereto. For example, when the machine tool includes a robot movable with respect to the chuck 1, the measuring instrument 6 may be attached to the robot. For example, when the automatic claw changer 12 is attached to the distal end portion of the robot, the measuring instrument 6 may be attached to the automatic claw changer 12. Instead of the hand 22 of the loader 2, the measuring instrument 6 may be attached to a tool post (also referred to as a turret) used for processing the workpiece W or a milling spindle for rotating a tool.

In the above-described embodiment, an example in which the chuck 1 includes three claws 4 is described. However, the number of the claws 4 is not limited to this, and may be two or four or more.

In the above-described embodiment, an example in which the chuck 1 is a chuck of a machine tool is described. However, the present embodiment is not limited to this, and can be applied to a chuck used in an inspection apparatus. In this case, the gripping accuracy of the chuck 1 of the present embodiment can be confirmed to ensure the inspection accuracy of the workpiece W by the inspection apparatus.

The present invention is not limited to the above-described embodiments, and can be implemented by appropriately changing a part of the configuration without departing from the scope of the invention.

Claims

1. A chuck gripping accuracy confirming method for confirming gripping accuracy by gripping a measurement object to a chuck jaw,

the method comprises the following steps:

a grasping step of grasping the measurement object by the claw;

and a measuring step of measuring the vibration of the measurement object by the measuring instrument while rotating the chuck by driving a rotation driving unit.

2. The method of confirming gripping accuracy of a chuck according to claim 1,

the moving body driving section includes a lifting driving section that lifts the moving body, an axial movement driving section that moves the moving body in an axial direction of the chuck, and a lateral movement driving section that moves the moving body in a lateral direction when viewed in the axial direction.

3. The method of confirming gripping accuracy of a chuck according to claim 1 or 2,

the measurement step includes a first measurement step of measuring vibration of the cylindrical outer peripheral surface of the object to be measured, and a second measurement step of measuring vibration of the distal end surface of the object to be measured.

4. The method of confirming gripping accuracy of a chuck according to claim 3,

the measuring device includes a first measuring device capable of measuring vertical displacement and a second measuring device capable of measuring horizontal displacement.

5. The method for confirming gripping accuracy of a chuck according to claim 4,

after the first measurement step, the movable body is moved to a position where the second measurement instrument can measure the vibration of the object to be measured by driving the movable body driving unit,

in the second measuring step, the vibration of the distal end surface of the object to be measured is measured by the second measuring instrument.

6. The method for confirming gripping accuracy of a chuck according to any one of claims 1 to 5,

in the gripping step, the object to be measured is carried to the chuck by the moving body.

7. A method of jaw replacement of a chuck comprising:

a replacement step of replacing the chuck jaws; and

a gripping accuracy confirmation step of confirming the gripping accuracy of the chuck after the replacement step by the method for confirming the gripping accuracy of the chuck according to any one of claims 1 to 5.

8. A gripping accuracy confirming device for a chuck, which grasps a measurement object to a jaw of the chuck and confirms gripping accuracy,

the method comprises the following steps:

a rotation driving part that rotates the chuck;

a moving body movably provided with respect to the chuck;

a movable body driving unit that moves the movable body relative to the measurement target;

a measuring device that is provided on the movable body and measures vibration of the measurement target; and

a control part for controlling the operation of the display device,

9. The gripping accuracy confirmation apparatus of a chuck according to claim 8,

10. The gripping accuracy confirmation apparatus of a chuck according to claim 8 or 9,

11. The gripping accuracy confirmation apparatus of a chuck according to claim 10,

the control unit controls the movable body driving unit and the measuring device such that the movable body is moved to a position where the first measuring device can measure the vibration of the cylindrical outer peripheral surface of the object to be measured, the vibration of the cylindrical outer peripheral surface of the object to be measured is measured by the first measuring device, the movable body is moved to a position where the second measuring device can measure the vibration of the distal end surface of the object to be measured, and the vibration of the distal end surface of the object to be measured is measured by the second measuring device.

12. The gripping accuracy confirmation apparatus for a chuck according to any one of claims 8 to 11,

the movable body can carry the object to be measured to the chuck.